Azo dyestuffs



Patented Feb. 23, 1932 UNITED STATES PATENI; OFFICE HANS KRZIKALLA, OF MANNHEIM, GERMANY, ASSIGNOR TO GENERAL ANILINE WORKS,

INQ, OF NEW YORK, 1 T. Y., A CORPORATION OF DELAWARE .AZO DYESTUFFS No Drawing. Application filed July 22, 1930, Serial No. 469,926,3116. in Germany July 27, 1929.

HO N

in which X stands for an amide of an acid radicle selected from the group consisting of sulphonic and carboxylic acid radicles, R for an aryl radicle which may be further substituted, and R for a salicylic acid radicle which may be further substituted.

These dyestuffs give good, even, usually yellow to orange dyeings of very good properties as regards fastness which are still further improved by after chroming on the fibre. The complex chromium compounds of the said dyestuffs may also be produced by chroming the dyestufis in substance by the usual methods. The dyestuifs containing sulphonic groups may be converted into lakes with barium or calcium salts and may then be employed as wall paper colours, graphic colours and the like.

The following example will further illustrate the nature of this invention, but the invention is not restricted thereto. The parts are by weight.

Ewample 1 172 parts of metanilic acid amide are diazotized in the usual manner in parts of approximately per cent hydrochloric acid with 7 parts of sodium nitrite while cooling with ice and the whole is then allowed to flow into a solution of 34 parts of (2'-hydroxy-3- carboxy-5-sulpho) -1-phenyl-3-methyl-5-pyrazolone containing an excess of sodium carbonate. The formation of the dyestuif is completed very rapidly. After salting out, ayellow dyestuif is'obtained which dyes wool uniform greenish yellow shades and has a very good fastness to light.

By boilingthe dyestuft so obtained with an aqueous solution of chromium formate the complex chromium compound is obtained which likewise dyes wool uniform beautiful Example 2 13.6 parts of m-amino benzoic acid amide are diazotized as described in the foregoing example and coupled with 34 parts of (2-hydroxy- 3 carhoxy- 5 sulpho) 1 phenyl -'3- methyl-5-pyrazolone dissolved in a solution rendered alkaline by sodium carbonate. The readily formed dyestuff is a yellow powder which when boiled for a short time with an aqueous solution of an excess of chromium formate, gives a complex chromium compound which dyes wool yellow shades fast to light, washing and milling.

The dyestuffs derived from amino-benzene carboxylic acid amides which are substituted by halogen atoms or nitro groups in the benzene ring diifer only slightly from the corresponding non-substituted dyestuffs. Frequently the colour is changed only slightly to red by such substitution.

What I claim is:

1. As a new article of manufacture the azo dyestuff corresponding to the formula:

forming a yellow powder and dyeing wool fast even greenish yellow shades.

2. As new articles of manufacture azo dye stuffs corresponding to the formula:

in which X stands for an amide of an acid i'adicle selected from the group consisting of sulphonic and carboxylic acid radicles, R for a radicle of the benzene series which may be substituted by halogen or nitro groups, and R for a salicylic acid radicle which may be substituted by a sulphonic acid group.

In testimony whereof I have hereunto set my hand.

HANS KRZIKALLA. 

